Tuesday, September 24, 2013

Rapid Fishwatching Survey in Greek mountain waters!

More snorkeling photos to show the beauty - the amazing feeling - of snorkeling in mountain waters. Our HCMR surveys in these waters are going to be scientific - very meticulous - measuring many details not just fishwatching; however, anyone can snorkel. If you can take nature notes of what they see, and/or take photos you can participate in a natural history learning project. During our recent initial survey in the Pindos Mountains we just applied this kind of protocol - what is simply called a "look-see" approach.

If you do take notes you can actually implement a Rapid Fishwatching Survey (RFS) which is nothing more than a simple look-see technique yourself. Here I introduce the method in brief.

This is all you need:

-Underwater notepad
-Watch to keep track of time
-U/w Camera is optional but may really help identification/documentation

What you do:

First decide where you will snorkel and why. Each site snorkeled is one "sample" that is recorded in a database. At each site try to snorkel a fair length, taking in all representative habitat types. Usually a river length of at least 20 times the river width is appropriate. A key objective is to observe and record the "structure of the fish community"; and different fishes and different fish size-categories will be in different habitats. Try to spend at least 30 minutes looking for fish. Spend time floating motionless. Always record precisely the time entering and leaving the water - in this way you will know that at some sites you may have under-recorded or poorly "sampled" due to less time (so time is a measure of a "unit of effort"). Record habitat conditions (i.e. give the habitat types you surveyed in percentage categories pool: 40%, Run 20%, Riffle 10%, Glide: 29%, Rapid 1%). Also give a similar percent estimation of substrate type (rock, boulder, cobble,pebble, gravel, sand etc). Refer to woody debris or other special habitat conditions (marshes, backwaters, deeper reaches, springs) and provide references to species behaviour. Record other species observed (frogs, snakes). Photograph or film the reach you sampled above and below water.

The most important thing is the "species list" for each RFS sample. The idea is to record the numbers of each species (and usually the numbers per size-class category). This may be done in various ways depending on your personal interest and level of rigor. The simplest list is a check-list with rough numbers and notes. The most important thing is to find a way of doing this and keeping it consistent. Most people keep size-class data (i.e. they divide fish seen not only in species units but species size-class categories). Size is a very important attribute of the community of fishes.

For example,

A hypothetical sample list can be like this:

Epirus riffle dace: 20 (<5 cm), 5 (6-10 cm), 1(11-15 cm)
Peloponnesian Chub: 100s (<5), 20s (6-10 cm), 50s (11-15 cm), 1(c. 40 cm).
Peloponnesian Barble: 1000s (<5). Note: no adult fish seen!!!

Note that the 100s, 10s means hundreds, tens; and this is a very very rough 'guesstimated' statement - this is a low-rigour way of giving relative semi-quantitative appraisals. But its MUCH BETTER than saying "many, lots, abundant". Also the "c." shows that the length for the particular individual fish is estimated roughly.

So buy a wetsuit and think of snorkelling with a purpose....


This post photographically supplements my report during our inception survey in the EcoFlow project. All snapshots below are taken in the upper Acheloos and Aracthos river basins in the Pindos Mountains of Northwestern Greece during five days in mid september 2013. For more about this trip see my first posting below.


(...press photos below, to enlarge!)

Friday, September 20, 2013

Eels!!! Fish Kill at Oroklini Lake, Cyprus

Like  a "Pollack painting" a mass fish kill above the sluice at Oroklini Lake, Cyprus (Photo by Melpo Apostolidou / BirdLife Cyprus in late August)

September 7th 2013

Fish-kills are often the first signs of stress in an inland water body. Most times these are not naturally occurring events, especially when an endangered species is concerned: In this case Eels on Cyprus!

The European Eel (Anguilla anguilla) is scarce and critically threatened on Cyprus. It has declined dramatically on the island. IUCN lists the European Eel as "Critical" (i.e. critically endangered, the highest category of threatenedness). So when naturalists found a very large number of dead and dying eels at Lake Oroklini near Larnaka they were at once shocked and confused. What and why???

A few weekends ago, I flew over to Larnaka and was shown the dead eels. My friends were on hand to help with counting the eels and studying the problem (**see footnote). I am making some "results" public pre-maturely because many people have asked me about this problem. We are gathering data and analyzing all we collected to research the problem. So results and interpretations are still "preliminary".


1. We found groups of dead eels at five locations at Oroklini Lake. The total number of dead Eels that we saw was estimated at no less than 1200 individuals. But the fish-kill could realistically be double or tripple this number. But, to be conservative, we will record this Fish Kill at 1200.

2. At one point more than 450 eels had died in a dessicated channel since they were forced by a low concrete sluice and these were easily counted since they were concentrated in an area of only 65 square meters (see photos).

3. We manually measured the total length (TL) of a sub-sample of 200 Eels at the sluice in order to check the age-class structure of the doomed fishes. The sizes ranged from 17.7 cm (the smallest) to 59.1 cm. The overwhelming majority of the eels was 28 to 40 cm approximately.

4. Generally at other locations where we saw and photographed dead eels, most individuals were under 45 cm. Isolated individuals exceeding 60 cm were seen, but these larger fish were extremely scarce. So, the cohort of larger female Eels  -which need more than 10 years to mature in inland waters- was probably not in our obseverd records here. (Hopefully, some larger specimens have survived upstream somewhere..).

5. A lot of the "stranded" or dead fish were obviously consumed by predators; I believe this has been taking place as Oroklini's waters begun to shrink at least since April (see photo-trap snapshots). I assume in mid-summer more and more fish crowded in shrinking pools attracting predators. I roughly estimate that the peak of the mass-dying eel concentration episode lasted at least 100 days and this was taking place at various locations in Oroklini - not just the notorious sluice site (at least 3 locations). I estimate predators (birds, foxes) fed on at least 20 eels per day at least during this drying summer period. So at least 2000 eels most probably perished like this also. BirdLife Cyprus provided me with photos of three heron species feeding on Eels like this before the peak dessication begun (in spring). So, the c. 2000 devoured eels is a minimum number and again an obvious underestimate. However, it shows that the numbers of eels that Lake Oroklini sustains is higher than anyone could imagine for a Cyprus wetland!

Night photos taken by a photo-trap at the North-west end of Oroklini (at the Sluice). Six photos show birds feeding on eels in mid spring, between 29/4 – 15/5 2013. Some photos show birds feeding on eels at a high frequency (2 minutes between feeding). Three birds were identified as predators (this is a Night-Heron). Photo provided by BirdLife Cyprus.

Night photos taken by a photo-trap showing Grey Heron feeding on Eel. The other species also feeding was probably a Purple Heron. Photo provided by BirdLife Cyprus.

Why a a mass death of eels?

These are the following reasons we believe eels died like this here:

1. Simply they could not find adequate aquatic refugia since the artificially fragmented waters (the slucies, plugged culverts, canals) dried-up and the fish died. Fish simply died since the waters dried-out completely and they could not move away - although water does exist in a fairly large area even during late Summer at Oroklini.

2. Where the fish did find deeper permenant waters, the water became polluted, highly eutrophic and with very low oxygen and very high salinities. The fish could not stand this stress and slowly died. (Here we found many eels in various stages of decomposition, so they did not all die at once). We also found two large grey-mullets (Mugilidae sp.) that had died in these canals (and the bones of at least one grey-mullet with the 450 eels above the dried-out sluice). The populations of Mosquito fish were also lower in these high-saline canals, but we found no dead mosquitofish. The canal with the most dead eels had stagnant near-hypoxic conditions with very little life (even an absence of preceptable insect life). Most of the dead eels seen in water where at this stagnant disconnected cannal.

Have I ever seen such Eel-death 'carnage' before?

Not in Cyprus. Yes, in Greece: at Schnias Marathon National Park (near Athens) in 2010. Similarly a problem with a badly placed sluice.The 2010 fish kill at Schnias probably involved 2000 Eels! I recently mentioned this problem in blog post since we found "entrapped" eels here again (http://zogaris.blogspot.gr/2013/08/schinias-national-park-ichthyo-tragedy.html).

Why is this mass death event so important for Cyprus ichthyology?

1. We know very little about eels on Cyprus; some people think they are nearly extinct there (although many people know that in the past they were widespread on the island). The eel is an important indicator of river basin integrity- it needs un-impeded access to the sea, wet refugia during dry-hard times, reasonable-quality waters and food (a functioning rich food-web since Eels are carnivores). So since Cyprus's rivers and wetlands have been anthropogenically "trashed" - Eels are thought to be extinct by most people! (We did a questionnaire about this a couple of year back...).

2. Cyprus' society doesn't really seem to care about Eels. So nobody really wants to research them. (Perhaps because it is dirty work - muddy  diffiult waters - can't electrofish in high-conductivity water; eels are slimy etc etc.- I suppose....).

3. It should be said that the Oroklini event is definately the LARGEST ever recorded fish-kill of eels on Cyprus. Eels are extremely scarce and cryptic on Cyprus - and many people think they are totally absent or extinct - so this is a surprise!. Our recent HCMR-ISA project funded by the Water Development Department located eels in only 14 places among 170 surveyed sites on the island! Eel deaths (less than 10 individuals...) have been recorded at the Ezousa River and at the Diarizos River Mouth in the last 5 years. More on this will be published in an upcoming scientific paper.

This "find" of so many Eels shows that contrary to past research and public opinion fairly large numbers of eels enter Cyprus's inland waters. Obviously they don't survive well here. And humans are responsible.

How can we protect Eels and their inland water fish-communities on Cyprus?

1. Manage and restore habitats for Eels; and I mean intentionally with a scientific strategy and detailed conservation plannign...in order to provide for their migration, staging, movement, survival needs.

2. Prioritize site conservation on selected river basins where we know Eels exist in large numbers: Oroklini, Chrysochou, Ezousa, Diarizos, Pediaios, Chapotami, Germasogeia, Pyrgos. Concentrate actions to protect and enhance habitat for eels there first.

3. Do more conservation-relevant research Eels. Inventory eel habitats and their barriers to migration; get students involved in the study. Study local consevation needs of the eels.

4. Employ eels and fish research in inland water biological assessment; especially when providing measures for restoration.

5. Get the public interested. Scientists should speak-out first. Scientists have factual specific and constructive things to say about Eels- many people have a poor awareness about eels. Awareness, education, and a general sensitization are critically missing on the subject of native fishes on Cyprus. Eels are migratory fish: at least we could celebrate World Fish Migration Day (24th May...).

The Eel could become a conservation icon in Cyprus - an eastern-most survival outpost for this threatened migratory fish.

**I thank BirdLife Cyprus and the following friends who assisted with fish-work in the usual dirty-slimy-hot conditions: BIG Thanks to:Iakovos Tzortziis (aka Jacob), Melpo Apostolidou, Athina Papatheodoulou, and Elli Tzirkali. For more information about Oroklini please see BirdLife Cyprus at http://www.birdlifecyprus.org/en/html-27-LIFE_Oroklini.html and the project site: http://www.orokliniproject.org

Photos from three visits for survey and sampling in early September 2013 follow.

The "notorious" Sluice. Above this low concrete sluice is the major upland basin of Oroklini Lake. Hundreds of stranded Eels died here since the entire upland basin dries out in Summer. 
Athina Papatheodoulou with 450 eels immediately above the Sluice. My Zeiss binoculars are on the ground for scale (Left).
North-South Canal. Terribly close to new subdivision buildings and hydrologically isolated. Some living eels were still in this 525 m long isolated water body.

Dozens of decomposing Eels of the surface of "South Canal" immediately West of the North-South Canal. This canal turned pink and was probably nearly anoxic!

Decomposing Eels and my hand for Scale. These are in the "North" Canal which was a lot less hypoxic. Eels were in various stages of decomposition - so they did not all die at once. A long gradual death means many dead ones are not apparant. Again supporting that my fish kill estimation is probably a gross understatement.

Salt flats and totally salted-over remnant pools in the Oroklini Basin. Salina like flats are natural in parts of coastal lagoon depressions so this is not a problem (and it keeps the Phragmites low and mudflats extensive...). But, did the Eels escape this sudden salt-dessication?
Salted-over remnant pool in the main lagoon's basin. Under the encrusted salt its still wet and muddy.
Total contrast 300 meters upstream of the "Salted Basin"...A small creek enters Oroklini Lake from below the Larnaka-Agia Napa Highway. Waters are slightly brakish and Phragmites reeds are robust and thick.
Jacob in his '70s look volunteering to do all the chemical water samplings.
Jacob and I collecting parameters at each and every water body of the wetland (North-South Canal).
East Canal near the Beach. Next to the "Galazio Kyma" shoreline cafe. Slightly brakish water and Mosquitofish survived in this tiny refuge; it is actually an extension of the North-East Canal. 
A relatively HUGE wetland basin exists immediatly north of the Larnaka-Agia Napa Highway. Two small canals feed Oroklini with "freshwater run-off" from here. Much of the catchment is being build-up fast.
"West Canal". Immediately west of the lake.

"West Canal". Immediately upstream of the coast road to Larnaka Port. Big Grey-Mullets, Eels and Mosquitofish survive in here even in late summer. Slightly upstream of the palms the concrete canal is totaly dry.
"West Canal" upstream of its long concrete section. There is water here!!! And living eels! 
West Canal upland.
West Canald Upland. At some points the water was clear others turbid. We saw one Eel from observing from the bank. Both West Canal and East Canal are very important for allowing eel passage into Oroklini. And both harbour eels during the difficult summer period. 

Tuesday, September 17, 2013

EcoFlow Snorkeling Research in the Pindos Mountains

The Melissourgiotikos Tributary of the Kalaritikos (Arachthos) in The National Park of Tzoumerka, Peristeri and Arachthos Gorge

Mid September 2013

Ok, some trips you really remember, and this is a first-timer for us.
This is the first time HCMR officially has a project involving river science by observing fishes with mask and snorkel! And it is the first time any such fish-based micro-habitat suitability work has been officially researched by a scientific snorkeling method in Greece!

As most of my readers know, I love snorkeling. I have bought 7 mm thick wetsuits and used them in cold trout streams but I have never done a scientific survey using them. So now is the time - and our project is called EcoFlow!!!

Our Hellenic-Spanish field team finally got to do this amazing challenge: to attempt to use fishes and their habitat requirements for estimating environmentally-acceptable flow regimes below dams and water abstraction points. To do this right first you need to meticulously measure and understand the specific micro-habitat needs of the local fishes in natural conditions. We are concentrating our work on the mountain and upland streams in this multiple-partner project (funded by the Hellenic General Secretariat of Research and Technology). In four field days in mid September we inspected 12 sites in several upland tributaries of the Acheloos and Kalaritikos Rivers. 

The fishes we observed in the mountain streams are the following:
  • West Balkan Trout Salmo fariodes (Ioniki Pestrofa) - ENDEMIC to Western Balkans.
  • Peloponnesian Barbel Barbus peloponnesius (Peloponnisiaki Briana) - ENDEMIC to Ionian Ecoregion.
  • Epirus Riffle Dace Telestes cf. pleurobipunctatus (Liara) - ENDEMIC to Ionian Ecoregion.
  • Peloponnesian Chub Squalius cf. peloponnensis (Potamokefalos Peloponnisou) - ENDEMIC to Ionian Ecoregion.
  • Albanian Barbel Luciobarbus albanicus (Strossidi) - ENDEMIC to Ionian Ecoregion.

In this list I give the modern Greek names in parentheses, two of the scientific names have a cf code (latin for confer) meaning that we are not positive that this is a valid name since we know that these fish populations are under taxonomic review and their names may soon change. Also I should note that Albanian Barbel has never been recorded in Albanian territory and is a local Greek endemic, however although the name was given by a mislabeling mishap by the original collector I prefer to use the older colloquial name "Albanian Barbel" than the modern nickname of Strossidi used by Kotellat and Freyhof (2007). (We have a lot of Albanian people living in the Hellenic Peninsula for centuries so it is quite appropriate that a Greek Endemic fish have this amusing name - no problem...).

Upland rivers are threatened by hydroelectric dams and other barriers and by water abstraction (and even river diversion projects). Our EcoFlow-funded research aims to help us better restore and prescribe more natural flow regimes in degraded rivers. We begin with the most beautiful of Greece's waters - mountain waters!

I post some of our snapshots from this inception field survey. I thank field team members, Elias Dimitriou, Christina Papadaki and our good friend Fransisco Martinez-Capel (from the Polytechnic University of Valencia). For more updates about our recently launched mulit-partner project check http://www.ecoflow.gr/en/

The local Peloponnesian Chub, so-called Squalius cf. peloponnesius (since the taxonomy is not fully clarified). Fish feeding in the water column, larger individuals are in the deeper pools. These ones are at the rather turbid lower Kalaritikos River in a 2 m deep pool (Arachthos Basin). 
One of my favorite fishes is Luciobarbus albanicus (Albanian Barbel or Strossidi). Shown here in a deep pool (1.8 m. deep) in the lower Kalaritikos. These fish grow big - sometimes over 50 cm TL - they need more water and they migrate great distances for spawning.
Christina Papadaki -PhD Candidate, and her supervisor Dr. Elias Dimitriou. They are very technical people. Where we collect data on fish behaviour we also must have detailed hydrological, hydraulic, micro-habitat variables and other parameters.
Dr. Martinez-Capel using the Go-Pro camera in a deep pool in the Upper Acheloos (near Gardiki Village). Water was about 10 m visibility here!
Yours truly, just enjoying the beautiful colours and light in the Acheloos - soon this reach near Alexiou Bridge may be flooded by the Mesochora Dam...what a sad disgrace!
West Balkan Trout Salmo fariodes in the Kamnaitikos. They had a bad year in 2013 here - big floods in February totally re-arranged the river bed and most of the younger fish are gone. Older, smarter fish survived.
West Balkan Trout (about 26 cm TL). A true survivor. Kamnaitikos Tributary of the Acheloos. Sadly many of these clear-water reaches are fiercely spear-fished by poachers.
The Peloponnesian Barbel is sensitive to siltation and flow-regime changes. This is macro photo of a fry (<5 cm TL) at Gardiki Bridge on the Acheloos.
Epirus Riffle Dace (Telestes cf. pleurobipunctatus) in the upper part of the Acheloos (Gardiki Bridge). Adults such as these (c. 12 cm) use woody structures for cover such as the colourful roots and caves to hide. Young fish feed in schools at the end of the riffles and the head of pools. 
A very small and slender Peloponnesian Chub (check ID?) at the Gardiki Bridge. I was surprised how scarce these fish were at this particular site after the big floods (They were common in 2004 here- my friends and I even flyfished for them here back then).
Big trout caught in camara flash!! Note the many over-turned cobbles shuffled around by the great flood that happened in February here at the Kamnaitikos.
More flood re-shuffling evidence from the Kamnaitikos due to the flood. When we fished this place in 2004 the pool here was deep - great for bathing in! Now it was full of cobbles-and-pebbles and very shallow.
A group of four adult-sized (12 cm +) Peloponnesian Barbels at the Kalaritikos. The photo is in the Montane Cyprinid Zone of the River where two Barbel species, coexist with dominant Peloponnesian Chub and Epirus Riffle Dace. Visibility in the Arachthos is not as good as the Acheloos.
Dr. Martinez-Capel in the Upper Kalaritikos (near Kipina Monastery). This site is a spring-fed cold water Trout Zone site but very near the lower braided river section so it does recieve some cyprinids at times.  After snorkeling this reach we saw that it had remarkably small numbers of trout (contrary to our 2004 electrofishing sample); a single Peloponnesian Barbel and several large Albanian Barbels. Water levels were low and the site is said to be illegally fished.
Fishwatching a the long deep pool at Gardiki  Bridge(Acheloos river). Most Vlach kids from Gardiki know this place as "the Beach". But despite the fine weather we were alone. Here the situation was probably "flood disturbed" (we saw: two trout, many Epirus Riffle Dace, quite a few Peloponnesian Barbels and what I think is a single Peloponnesian Chub-needs ID check- see above). I expected more fish here.